Fluid-motor and retarding device therefor.



J'. F. MOELROY. FLUID MOTOR AND-RETARDING 'DEVIGE THEREFOR.

APPLICATION FILED SEPT. 2, 1909. 1,1 18,29? Patented 310124, 1914.

3 SHEETSSHEET 1.

J. F. MOELROY. FLUID MOTOR AND RETARDING DEVICE THEREFOR.

APPLICATION FILED SEPT. 2, 1909. 1 11897 Patented Nov. 24, 1914.

3 SHEETS-SHEET 2.

J. P, MQBLROY. FLUID MOTOR AND RETARDING DEVICE THEREFOR.

APPLICATION FILED SEPT. 2, 1909. Patented Nov. 24:, 1914,

3 SHEETSSHEET 3.

an H.

1mm Im'Enm? aqm plied .with.

40 rate of speed, in order to 45 in order to avoid any UNITED STATS ATETOFFTQE.

JAMES F.

MQELROY. OF ALBANY, NEW YORK, ASSIGNOR TO CONSOLIDATED CAR- HEA'IINGCOMPANY. A CORPORATION OF WEST VIRGINIA.

FLUID-MOTOR AND RETABDING DEVICE THEREFOR.

Specification of Letters Patent.

Patented Nov. 24, 19141...

Application filed September 2, 1909. Serial No. 515,821.

of New York, have invented certain new and useful Improvements inFluidJvIotors and Retarding Devices Therctor, of which the following isa specification disclosing what I now consider the best of the variousforms in which the principle of my invention may be embodied.

My present invention relates to motors adapted to be operated bycompressed air, or other fluids, and has for its object the provision ofa motor particularly adapted.

to the peculiar requirements in the opening and closing of doors orgates on railway cars, having been recently put into service for thatpurpose on the subway cars in New York city, although it may also beapplied to any use in which a similar kind of ciprocating motion isdesired.

My invention will be more clearly understood by reference to thefollowing descrip- 5 tion and accompanying drawings.

In the use for which my invention is more especially intended, to-wit,the opening and closing of doors or gates on railway. cars, certainpeculiar conditions must be com- For instance, it is desirable that thedoor or gate should be operated by means of compressed air taken fromthe storage tank or other convenientpar't of the air.

brake system. It is also desirable that the motion of the door inclosing should be rapid for the greater part, of the doors travel, inorder to save time in closing the door, but that the latter part of thedoors travel should be accomplished at a very low avoid injury topassengers and slamming of the door. Itvis also desirable that themovement of the door should be accomplished with as littleexpenditure ofcompressed air as possible effect on the brakes. By means of my fluidmotor and retarding device I am enabled to attain these ob jects. 4

Referring to the drawings, Figures 1,

2 and 8 represent sectional views ofmy improved motor, shown applied toa sliding door, and show the relative positions of theparts during themovement of the. door. For inst-anceyif Fig. 1 be considered as showingthe door in the open position, Fig. 2

12, being compressed,

- will show the door-half open and Fig. 3

any improved motor. Figs. 10 and 11 are sectional views of this form ofvalve.

Referring to Fig. 1, it will be seen that my improved motor consists oftwo oppositely disposed cylinders 1 and 2, in which are reciprocatingpistons 3 and 4', respectively. T o pistons 3 and c are attached pistonrods 5 and 6, which are attached tov a common driving rod 7, by means ofa casting or stop 8, through which driving rod the door or other object9 is operated.

The retarding device attached to my improved motor consists of a tube 10which has stops 11, 11, at each end. Inside of the tube 1 place a spring12, the ends of which rest against washers 13, 13 which are arrested bythe stops. These washers are provided with holes permitting the passagethrough them of a rod 14 which is attached to a casting or link 15.Surrounding each end of rod 14 are sleeves 17, 17, which bear againstWashers 13, 13 and thus exert pressure upon stop 8. I provide a hole inlink 15 through which piston rod 6 moves,-and place a collar 18 aroundpiston rod 6, which collarbea-rs against link 15.

The source of supply of compressed fluid is connected to the operatingvalve 19 through pipe 20. In pipe 20 is inserted a disk 21 of metal, orother suitable material,

having a constricted opening.- Pipes 22 and 23 serve to transmit thecompressed fluid from the valve to and from the ends of cylinders 1 and2 respectively. Pipe 241 is the exhaust for compressed fluid after ithas been used.

The operation of my improved motor is as follows: \Vhen the motor andvalve 19 are in the position shown in Fig. 1, the door is in the openposition and compressed fluid is being admitted through pipes 20 andinto cylinder 1. When it is desired to close the door the valve is movedto the position shown in Fig. 2, which permits the compressed fluidcontained lncylinder 1 to How through pipes 22 and 23 into cylinder 2and exert a pressure upon piston 4:. The spring exerts a pressurethroughsleeve l'? and link 15 upon stop 8, thus giving the .motoradditional power which has been stored in the spring by its previouscompression due to its damping or retarding effect on the previousopening stroke. This aids it in overcoming the ini tial frictions andinertia of the door. The

piston 4 then moves as shown in Fig. 2, the pressure on the springhaving been released after the starting action aforesaid. The movement.of the valve is continued until it reaches the position shown at Fig. 3which permits compressed fluid to enter cylinder 2 through. pipes andand exhausts the" contents of cylinder 1 through pipes 22 and 24.

Owing to the constricted opening in disk 2.1 the pressure in cylinder 2is very much less than the pressure of the source of supply andcontinues so as long as there is but little opposition to the movementof the 20 door. It is however-adequate to continue at a rapid rate thedoor movement which has been initiated as aforesaid, the door at thispoint not being obstructed by the spring.

Piston 4 thus continues to move at low pressure until it brings upagainst collar '18,

tarding the movement of piston reason of the constricted opening in disk21;

the fluid in cylinder 2, when the movement of piston 4 is thus retarded,begins to accumulate and the pressure thereof to increase, so that aconstantly increasing pressure, slightly greater than the pressure ofspring 12, is maintained against the piston 4 op posing the pressure inthe spring and. toreing the door slowly shut. 1 am thus ,enabled to movethe door rapidly and with an expenditure of very little energy to apoint near the end of its movement, and then move it quitev slowly fromthat point on,

thus preventing injury to the passengers, slamming of the door, andrebound of the spring, and at the same time storing up in the springpower which will aidin initiating the next start of the door in thereverse especial object making the motor more com-' 5 ends adjacent butofiset and their piston rods direction as already described.

By varying the length of collar 18 I can make the relative length of thefast and slow movements of the door anything 1 choose. I find, however,that in practice it is-best to move the door at a high speed to aboutsix inches of the end of its travel. 1

I have illustrated in Figs. 4 and 5 a different arrangement of partshaving for its pact, the principle f-operation, however, is the same asthat of the arrangement shown in Figs. 1, 2 and 3. In this case 'thecylinders 1 and 2 are brought together with their inclusive.

5 and 6 connected with doorrod 7 by the castings 8 and '8, the sleeve 18being on piston-rod 5.

The valve which I prefer to use with -my improved motor is shown inFigs. 7 to 11 It consists of an outer shell or casing 31, in which ispivoted a valve stem 32 which is attached to a seat 33. Resting upon theseat 33 is a cap 34 which is held in contact with the seat by means of aspring 35, which presses against the cap and against the valve stem 32.The cap 34 is pivoted upon a pivot 36, and contains a plurality of portsshown in the drawings as three in number, 37, 38 and 39. The seat 33contains four openings 40, 41, 42 and 43, communicating with the pipingto and from the reservoir exhaust and motor by leaders and adapted toregister with the ports 37,

38 and 39. To the upper end of the valve stem 32 is attached anoperating handle 41") by which the valve stem may be turned. in

order to limit the motion of the valve stem I provide, preferablyintegral with the outer shell or casing 31, a stop 46 which limits themotion of the handle in one direction. The extent of motion of thehandle in the opposite direction is limitedby means of an adjustablestop here shown in the form of a screw 47.

For the purpose of facilitating cleaning and repairing, as well as toobtain amore intimate contact between the cap 34 and seat 33 Ipreferably make the valve stem 32 and cap 34 in separatepieces, theprojection 48 on the cap engaging a corresponding indentation'in thevalve stem 32', thus per mitting the cap 34 to be turned.

The position assumed .by the valve in itsoperation may best be seen fromFigs. 1,

'- 2 and 3.

Thus, in F 1, port 39 registers with openings 40 and 43 permittingcompressed fluid to flow from the reservoir through pipe- 20, opening43, port 39, opening 40 and pipe 22 to cylinder 1. The port 37 registerswith openings 31 and 32, permitting compressed fluid to] be exhaustedfrom cylinder 2 through pipe 23,'opening 41, port 37, opening 42 andpipe 24.

In the position shown' in Fig. 2, port 38 registers with openings 40 and41, thus permitting compressed fluid to flow between pistons 1 and 2,through pipe 22, opening 40, port 38, opening 41 and pipe 23.

This is the first position occupied by the valve in operating myimproved motor and 1'. am thereby enabled to use compressed fluid whichhas already done work in. propelling onejpiston to give the initialmovement to the other When the valve? is-in the positionshown in Fig. 3,port 39 registers with the openings .41 and 43, and compressed fluid isthereby admitted through pipe 20, opening 43, port 39, opening 41, andpipe 23, to cylinder 2.

Port 37 registers with the openings 40 and confine myselfto the precisedetails shown and described.

What I claim as new and desire to secure by Letters Patent is:

1. In a fluid motor the combination of a cylinder, a piston workingtherein and adapted to move a frictional load, a power storing elementarranged to be operated by said piston subsequently to the initialoperation of said frictional load, and means for maintaining a lowcylinder pressure during the initial movement of said frictional load,

and a high cylinder pressure during the remainder of the movementthereof.

2. In a fluid motor the combination of a cylinder, a piston workingtherein and adapted to move a frictional load, a power storing elementarranged to be operated by said piston subsequently to the initialoperation of said frictional load, means for providing a high pressurefluid supply, and meansconnected with said fluid supply for maintaininga low cylinder pressure during the initial movement of said frictionalload,

and a high cylinder pressure during the remainder of the movementthereof.

3. In a fluid motor the combination of a cylinder, a piston workingtherein and adapted to move a frictional load, a power storing elementarranged to be operated by said piston subsequently to the initialoperation of said frictional load, means for providing a high pressurefluid supply, a valve controlling said fluid supply, and a pipeconnected with said fluid supply and provided with a constricted outletfor maintaining a low cylinder pressure during the initial movement ofsaid frictional load, and a high cylinder pressure during the remainderof the movement thereof.

4. In a fluid motor the combination of a cylinder, a pistonworkingthereinand adapted to move a frictional load,a power storingelement arranged to be operated by said piston subsequently to theinitial operation of said frictional load, and a pressure reducer formaintaining a low cylinder pressure during the initial movement of saidfrictional load, and a high cylinder pressure during the remainder ofthe movement thereof.

5. In a fluid motor the combination of a cylinder, a piston workingtherein, a sleeve slidable 'n the cylinder and actuated by the piston,means actuated by the sleeve for re tarding the movement of the pistonduring a portion of its travel, and a fluid supply pipe provided withmeans to obtain a reduced pressure during the free movement of thepiston, and an increased pressure during the retarded movement of thepiston.

(5. In a fluid motor the combination with a cylinder, a piston workingtherein and adapted to move a frictional load throughout its entirestroke, a retarding element operated by said piston during a portion ofits stroke, means actuated by the retard ing element for retarding themovement of the piston, a valve controlling the fluid supply to saidcylinder, and a fluid supply pipe provided with means to maintain a lowpressure in the cylinder under the frictional load and relatively highpressure when the frictional load is augmented by said retardingelement.

' In a fluid motor, "a cylinder, a piston working therein, a sleeveactuated by the piston, means actuated by the sleeve for graduallyreducing the speed of the piston duringa portion of its stroke, a valvecontrolling the power, and a pipe provided with means cooperating withsaid valve to inplston as 5 crease 'the power applied to thethe speed ofits travel decreases.

8. In a fluid motor, a cylinder, apiston moving therein at a relativelyhigh speed during the initialpart of the stroke, a

sleeve in the cylinder and actuated by' the piston, means actuated bythe sleeve for reducing the speed of the piston during the latter partof its stroke, a valve controlling the pressure to said cylinder, and"an inlet pipe for saidvalve provided with means for admitting a;relatively smaller amount of fluid for a given distance of travel of thepiston during the initial portion of its stroke than during the latterpart of its stroke.

the piston rod for part of its length, a

spring external to the cylinder, a rod passing through said spring andcarrying at either end a sleeve adapted to engage. the spring, and alink attached to said rod and slidably engaging said piston-rod andadapted to be stop.

10. A door operating motor of the fluid pressure type comprising twoopposing sin-.

moved by said collar or said gle acting cylinders, pistons therein, a0011- nector for the piston, an operating device for the door,controlling valve admitting the fluid to and exhausting it from the twocylinders alternately, an actuating element carried by one cylinder andoperated by the piston therein at one portion of the pistons stroke, andretarding mechanism operated by said element.

11. A door operating motor comprising a pair of opposed cylinders,pistons and piston. rods therefor, means for connecting said rods, 2door operating rod carried by said connecting means, a sleeve in onecylinder and actuated by the piston therein, and means ectuatedby thesleeve for retarding the movements of said pistons during a portion oftheir travel.

1:2. A door operating motor comprising a cylinder, a piston therein, arod'for said piston, door operating means connected to said rod, asleeve in the. cylinder actuated by the piston therein, a rod slid-ablysup ported by the cylinder, ebutments carried by said slidable rod andengaging the sleeve, and a; spring coiled about the slidable rod andinterposed between the abutments and adapted to be compressed by theabutment to retard the movement of the piston.

In witness whereof l have hereunto set my hand, before two subscribingWitnesses, 25

this 7th day of May, 1909.

J AMES F. MCELROY. Witnesses BEULAH CABLE, Enxnsr D. JANSEN.

